Heat strain and heat stress for workers wearing protective suits at a hazardous waste site.
Am Ind Hyg Assoc J 1987 May; 48(5):458-463
A study was conducted on workers wearing protective suits in hot weather at a hazardous waste site to evaluate heat stress and heat strain under these conditions. The workers, five men aged 25 to 33 years, wore laminated polyvinyl-chloride/Tyvec chemical resistant hooded suits plus rubber boots, gloves, full facepiece dual cartridge respirators and hard hats. Work activities included walking to and from a large wastewater lagoon where they obtained water samples from a boat. Heart rate, oral temperature, self reported symptoms and environmental parameters were measured. Heart rate and symptoms of fatigue and weakness increased with increasing Wet Bulb Globe Temperature, an environmental index of heat stress. Temperatures measured inside the suits of two subjects were 36.5 degrees-C, which was higher than the ambient temperature. In an effort to relate the degree of heat strain for workers wearing full body protective suits to environmental factors, a comparison was made of heart rates for men working with and without suits. Heat stress equivalent to adding 6 to 11 degrees-C to the ambient Wet Bulb Globe Temperature index was found for those men wearing the protective clothing. The authors conclude that the wearing of vapor barrier clothing can greatly increase heat stress and also the risk of incurring heat induced illness. They recommend that workers be monitored at frequent intervals to prevent such illnesses. They also suggest that it may be useful to monitor skin temperature in addition to heart rate and core temperature to provide an additional criterion for cessation of work in the heat, as heat exhaustion collapse can occur at deep body temperatures as low as 38 degrees-C.
NIOSH-Publication; NIOSH-Grant; Heat-exhaustion; Heat-exposure; Personal-protective-equipment; Protective-clothing; Clothing; Hazardous-materials; Physiological-stress
American Industrial Hygiene Association Journal
Environmental Health Sciences Johns Hopkins University 615 North Wolfe Street Baltimore, MD 21205